1. Field of the Invention
This invention relates to flare gas burners and is more particularly concerned with an improved apparatus and method for smokeless burning of waste gas.
2. Description of the Prior Art
Many flare gas burners of varying degrees of complexity have been developed to improve combustion of waste (or "dump") gas and to suppress smoke and/or noise.
Illustratively, Zink U.S. Pat. No. 2,779,399 shows a flare stack burner having a series of pilot burners surrounding the main opening from which waste gas is discharged at high velocity by injecting a mixture of air and steam into the waste gas stream at a plurality of points.
Webster et al U.S. Pat. No. 2,891,607 provides a burner comprising a plurality of concentric pipes, the innermost pipe and the space between the two outermost pipes having steam discharge members for inducing air into the burning gases. The waste gas is delivered through an intermediate annular passage defined by the concentric pipes.
Procter U.S. Pat. No. 3,554,681 shows a flare burner provided with a frustoconical deflector which forms the upper end of the tip. A steam manifold encircles the tip and serves to induce air (via devices producing a Coanda effect) into the lower portion of the deflector. Waste gas is delivered to the tip via a gas stream diverter which displaces the stream towards the walls of the tip. The air streams and waste gas streams are caused to intersect at approximately 90 degrees.
Straitz U.S. Pat. No. 3,797,991 discloses a series of spaced apart steam nozzles for inducing air flow into the region above the flare tip. British Pat. No. 1,604,441 shows a similar device in which the nozzle devices produce a Coanda effect.
Straitz U.S. Pat. No. 3,994,671 teaches a flare gas burner comprising a plurality of concentric pipes by means of which the waste gas is delivered in a whirling path and caused to intersect with streams of air and steam, also in whirling paths, delivered by inner and outer pipes. A sound absorbing shroud and acoustical baffles are integrated into the device. Straitz U.S. Pat. No. 3,995,986 shows a related device.
Hemmer et al U.S. Pat. No. 4,019,852 shows a flare gas burner the tip of which is surrounded by an annular manifold from which a series of tubes project upwardly and outwardly. A stream of steam air is ejected through outwardly facing slits in said tubes and serves to draw atmospheric air between said tubes and into the stream of waste gas emerging from the tip.
German OLS No. 2 154 785 discloses a device for exhausting and purifying waste gas contaminated with phenol, resins and like material. The waste gas is passed through a first Venturi-like chamber having a flare burning in the throat thereof, the first chamber and associated flare projecting into the throat of a large Venturi which serves to induce a current of air to intermingle with the waste gas being exhausted.
European patent application No. 0054383 shows a flare gas burner using a Coanda effect and provided with a funnel shaped noise shield located below the tip.
The present invention provides a smokeless flare gas burner of greatly simplified construction and characterized by ease of maintenance, reduced noise level and high overall efficiency.